The purpose of this study is to determine the effects of long-term low dose ultra-A1 (320-400 nm) light on delayed type hypersensitivity, T-lymphocyte of subset populations, and t-lymphocyte function of normal human subjects as determined by in vitro lymphocyte assays. The same observations will be made on patients with systemic lupus erythematosus and the effects of this light on the laboratory and clinical parameters of SLE will be measured.